Cai and Wu [1]} considered a rare/weak model in which all features obey the same sparse mixture under the alternative, while the distributions defining this mixture are quite general. In particular, the setting of [1]} covers rare/weak feature models studied in
[3]}, [4]}, [5]}, [6]}, [7]}, [1]}. It does not cover, however, two-sample settings or cases where the features are not identically distributed as studied, for example, in [9]}, [10]}.
